linux_dsm_epyc7002/drivers/char/hw_random/powernv-rng.c
Chuhong Yuan 3e75241be8 hwrng: drivers - Use device-managed registration API
Use devm_hwrng_register to simplify the implementation.
Manual unregistration and some remove functions can be
removed now.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-02 14:44:33 +10:00

71 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2013 Michael Ellerman, Guo Chao, IBM Corp.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include <linux/hw_random.h>
static int powernv_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
unsigned long *buf;
int i, len;
/* We rely on rng_buffer_size() being >= sizeof(unsigned long) */
len = max / sizeof(unsigned long);
buf = (unsigned long *)data;
for (i = 0; i < len; i++)
powernv_get_random_long(buf++);
return len * sizeof(unsigned long);
}
static struct hwrng powernv_hwrng = {
.name = "powernv-rng",
.read = powernv_rng_read,
};
static int powernv_rng_probe(struct platform_device *pdev)
{
int rc;
rc = devm_hwrng_register(&pdev->dev, &powernv_hwrng);
if (rc) {
/* We only register one device, ignore any others */
if (rc == -EEXIST)
rc = -ENODEV;
return rc;
}
pr_info("Registered powernv hwrng.\n");
return 0;
}
static const struct of_device_id powernv_rng_match[] = {
{ .compatible = "ibm,power-rng",},
{},
};
MODULE_DEVICE_TABLE(of, powernv_rng_match);
static struct platform_driver powernv_rng_driver = {
.driver = {
.name = "powernv_rng",
.of_match_table = powernv_rng_match,
},
.probe = powernv_rng_probe,
};
module_platform_driver(powernv_rng_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Bare metal HWRNG driver for POWER7+ and above");